package dev2dev.textclient.conv;

/**
 * @author jinbing.yao
 * @createTime 2023-11-22 19:10
 **/
public class AudioConverter {

    private static final int[] ALAW_TABLE = {
            1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8,
            9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
            25, 27, 29, 31, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44,
            46, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62,
            64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
            81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96,
            97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112,
            113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128,
            128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,
            144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,
            160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175,
            176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,
            192, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206,
            207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222,
            223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238,
            240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255
    };

    public static void main(String[] args) {
//        short[] pcmData = { /* PCM data */ };
//        byte[] alawData = convertPcmToAlaw(pcmData);
        // Do something with the ALAW data
    }

    public static byte[] convertPcmToAlaw(byte[] pcmData) {
        byte[] alawData = new byte[pcmData.length];

        for (int i = 0; i < pcmData.length; i++) {
            alawData[i] = pcmToAlaw(pcmData[i]);
        }

        return alawData;
    }

    private static byte pcmToAlaw(short pcm) {
        int sign = (pcm & 0x8000) >> 8;
        if (sign != 0) {
            pcm = (short) -pcm;
        }
        if (pcm > 32635) {
            pcm = 32635;
        }
        pcm = (short) (pcm + 132);
        int exponent = 7 - (int) (Math.log(0x7F + pcm) / Math.log(2));
        int mantissa = (pcm >> (exponent + 3)) & 0x0F;
        int alaw = ~(sign | (exponent << 4) | mantissa);

        return (byte) (alaw & 0xFF);
    }
}
